Periodico Di Mineralogia Vol 82 3 December 2013

Download Periodico Di Mineralogia Vol 82 3 December 2013 full books in PDF, epub, and Kindle. Read online Periodico Di Mineralogia Vol 82 3 December 2013 ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!

Periodico di Mineralogia Vol. 82, 3 december 2013

Download Periodico di Mineralogia Vol. 82, 3 december 2013 PDF Online Free

Author : Antonio Gianfagna
Publisher : Edizioni Nuova Cultura
ISBN 13 : 8868122367
Total Pages : 232 pages
Book Rating : 4.8/5 (681 download)

Book Synopsis Periodico di Mineralogia Vol. 82, 3 december 2013 by : Antonio Gianfagna

Download or read book Periodico di Mineralogia Vol. 82, 3 december 2013 written by Antonio Gianfagna and published by Edizioni Nuova Cultura. This book was released on 2014-02-07 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Raffaella De Luca, Miguel Angel Cau Ontiveros, Domenico Miriello, Alessandra Pecci, Emilia Le Pera, Andrea Bloise and Gino Mirocle Crisci, Archaeometric study of mortars and plasters from the Roman City of Pollentia (Mallorca - Balearic Islands) Fabio Fratini, Andrea Cagnini, Simone Porcinai, Paola Lorenzi and Stefano Pasolini, An unusual mortar with a magnesium binder in the Perseus of Giovan Battista Pieratti in Boboli Gardens (Florence) Alessandra Pecci, Almost ten years of plasters residue analysis in Italy: activity areas and the function of structures Cristiana Nunes, Zuzana Slížková and Dana Křivánková, Lime-based mortars with linseed oil: sodium chloride resistance assessment and characterization of the degraded material Maria Elena Moschella, Walter Canavesio, Mariano Cristellotti and Emanuele Costa, Investigation about ancient mortars and plasters in the Mondovì cathedral (Cuneo, Italy) Vincenzina La Spina, Fabio Fratini, Emma Cantisani, Camilla Mileto and Fernando Vegas López-Manzanares, The ancient gypsum mortars of the historical façades in the city center of Valencia (Spain) Alessandra Bonazza, Chiara Ciantelli, Alessandro Sardella, Elena Pecchioni, Orlando Favoni, Irene Natali and Cristina Sabbioni, Characterization of hydraulic mortars from archaeological complexes in Petra Letizia Bonizzoni, Valentina Brunello and Simone Caglio, Scientific analyses beyond the excavation: studies for a non invasive preliminary approach Rossella Agostino, Germana Barone, Paolo Mazzoleni, Simona Raneri, Giuseppe Sabatino and Maria Maddalena Sica, Mortars and plasters from the Bruttii - Roman city of Taureana (Palmi, RC, Italy) - preliminary data Deodato Tapete, Fabio Fratini, Barbara Mazzei, Emma Cantisani and Elena Pecchioni, Petrographic study of lime-based mortars and carbonate incrustation processes of mural paintings in Roman catacombs Nadia Bianco, Angela Calia, Giampiero Denotarpietro and Pietro Negro, Hydraulic mortar and problems related to the suitability for restoration Sergio Sfrecola, Stefano Vassallo and Paola Parodi, Genoese “intonachino” plasters between the 12th and the 18th century: archaeometric analyses Claudia Pelosi, Ulderico Santamaria, Giorgia Agresti, Giulia De Vivo and Davide Bandera, Analysis and laboratory tests to evaluate the composition and the behaviour of some dehumidifying mortars used in the restoration field

Periodico di Mineralogia Vol. 84, 3B (Special Issue), December, 2015

Download Periodico di Mineralogia Vol. 84, 3B (Special Issue), December, 2015 PDF Online Free

Author : Eugenio Fazio
Publisher : Edizioni Nuova Cultura
ISBN 13 : 8868125935
Total Pages : 250 pages
Book Rating : 4.8/5 (681 download)

Book Synopsis Periodico di Mineralogia Vol. 84, 3B (Special Issue), December, 2015 by : Eugenio Fazio

Download or read book Periodico di Mineralogia Vol. 84, 3B (Special Issue), December, 2015 written by Eugenio Fazio and published by Edizioni Nuova Cultura. This book was released on 2016-02-04 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: CONTENTS Omar Bartoli, Antonio Acosta-Vigil and Bernardo Cesare High-temperature metamorphism and crustal melting: working with melt inclusions Igor M. Villa 39Ar-40Ar geochronology of mono- and polymetamorphic basements Antonio Langone and Massimo Tiepolo U-Th-Pb “multi-phase” approach to the study of crystalline basement: application to the northernmost sector of the Ivrea-Verbano Zone (Alps) Gabriele Cruciani, Chiara Montomoli, Rodolfo Carosi, Marcello Franceschelli and Mariano Puxeddu Continental collision from two perspectives: a review of Variscan metamorphism and deformation in northern Sardinia Rosolino Cirrincione, Eugenio Fazio, Patrizia Fiannacca, Gaetano Ortolano, Antonino Pezzino and Rosalda Punturo The Calabria-Peloritani Orogen, a composite terrane in Central Mediterranean; its overall architecture and geodynamic significance for a pre-Alpine scenario around the Tethyan basin Gisella Rebay, Maria Pia Riccardi and Maria Iole Spalla Fluid rock interactions as recorded by Cl-rich amphiboles from continental and oceanic crust of italian orogenic belts Guido Gosso, Gisella Rebay, Manuel Roda, Maria Iole Spalla, Massimo Tarallo, Davide Zanoni and Michele Zucali Taking advantage of petrostructural heterogeneities in subduction-collisional orogens, and effect on the scale of analysis

Mineralogical Application on Environments, Archeometry and Cultural Heritage

Download Mineralogical Application on Environments, Archeometry and Cultural Heritage PDF Online Free

Author : Antonio Gianfagna
Publisher : Edizioni Nuova Cultura
ISBN 13 : 8868120674
Total Pages : 222 pages
Book Rating : 4.8/5 (681 download)

Book Synopsis Mineralogical Application on Environments, Archeometry and Cultural Heritage by : Antonio Gianfagna

Download or read book Mineralogical Application on Environments, Archeometry and Cultural Heritage written by Antonio Gianfagna and published by Edizioni Nuova Cultura. This book was released on 2013 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Alkaline Rocks and Carbonatites of the World, Part 4

Download Alkaline Rocks and Carbonatites of the World, Part 4 PDF Online Free

Author : A.R. Woolley
Publisher : Geological Society of London
ISBN 13 : 1786204452
Total Pages : 578 pages
Book Rating : 4.7/5 (862 download)

Book Synopsis Alkaline Rocks and Carbonatites of the World, Part 4 by : A.R. Woolley

Download or read book Alkaline Rocks and Carbonatites of the World, Part 4 written by A.R. Woolley and published by Geological Society of London. This book was released on 2019-09-02 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: The alkaline igneous rocks and carbonatites are compositionally and mineralogically the most diverse of all igneous rocks and, apart from their scientific interest, are of major, and growing, economic importance. They are important repositories of certain metals and commodities, indeed the only significant sources of some of them, and include Nb, the rare earths, Cu, V, diamond, phosphate, vermiculite, bauxite, raw materials for the manufacture of ceramics, and potentially Th and U. The economic potential of these rocks is now widely appreciated, particularly since the commencement of the mining of the Palabora carbonatite for copper and a host of valuable by-products. Similarly, the crucial economic dominance of rare earth production from carbonatite-related occurrences in China, has stimulated the world-wide hunt for similar deposits. This volume describes and provides ready access to the literature for all known occurrences of alkaline igneous rocks and carbonatites of Antarctica, Asia and Europe excluding the former USSR, Australasia and oceanic islands. More than 1,200 occurrences from 59 countries are outlined together with those of 57 oceanic islands and island groups. The descriptions include geographical coordinates and information on general geology, rock types, petrography, mineralogy, age and economic aspects with the principal references cited. There are 429 geological and distribution maps and a locality index. As has been demonstrated by the three earlier volumes, the present book is likely to be of considerable interest to mineral exploration companies, as there are no comprehensive published reviews of the economic aspects of the alkaline rocks. It will also interest research scientists in the fields of igneous petrology and volcanology, and geologists concerned with the regional distribution of igneous rocks and their geodynamic relationships.

The Geology of New Jersey

Download The Geology of New Jersey PDF Online Free

Author : Henry Barnard Kummel
Publisher : Franklin Classics
ISBN 13 : 9780342421176
Total Pages : 156 pages
Book Rating : 4.4/5 (211 download)

Book Synopsis The Geology of New Jersey by : Henry Barnard Kummel

Download or read book The Geology of New Jersey written by Henry Barnard Kummel and published by Franklin Classics. This book was released on 2018-10-11 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. To ensure a quality reading experience, this work has been proofread and republished using a format that seamlessly blends the original graphical elements with text in an easy-to-read typeface. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Volcanism in Antarctica: 200 Million Years of Subduction, Rifting and Continental Break-up

Download Volcanism in Antarctica: 200 Million Years of Subduction, Rifting and Continental Break-up PDF Online Free

Author : J.L. Smellie
Publisher : Geological Society of London
ISBN 13 : 178620536X
Total Pages : 802 pages
Book Rating : 4.7/5 (862 download)

Book Synopsis Volcanism in Antarctica: 200 Million Years of Subduction, Rifting and Continental Break-up by : J.L. Smellie

Download or read book Volcanism in Antarctica: 200 Million Years of Subduction, Rifting and Continental Break-up written by J.L. Smellie and published by Geological Society of London. This book was released on 2021-06-09 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt: This memoir is the first to review all of Antarctica’s volcanism between 200 million years ago and the Present. The region is still volcanically active. The volume is an amalgamation of in-depth syntheses, which are presented within distinctly different tectonic settings. Each is described in terms of (1) the volcanology and eruptive palaeoenvironments; (2) petrology and origin of magma; and (3) active volcanism, including tephrochronology. Important volcanic episodes include: astonishingly voluminous mafic and felsic volcanic deposits associated with the Jurassic break-up of Gondwana; the construction and progressive demise of a major Jurassic to Present continental arc, including back-arc alkaline basalts and volcanism in a young ensialic marginal basin; Miocene to Pleistocene mafic volcanism associated with post-subduction slab-window formation; numerous Neogene alkaline volcanoes, including the massive Erebus volcano and its persistent phonolitic lava lake, that are widely distributed within and adjacent to one of the world’s major zones of lithospheric extension (the West Antarctic Rift System); and very young ultrapotassic volcanism erupted subglacially and forming a world-wide type example (Gaussberg).

The Contribution of Mineralogy to Cultural Heritage

Download The Contribution of Mineralogy to Cultural Heritage PDF Online Free

Author : Gilberto Artioli
Publisher : Emu Notes in Mineralogy
ISBN 13 : 9780903056618
Total Pages : 462 pages
Book Rating : 4.0/5 (566 download)

Book Synopsis The Contribution of Mineralogy to Cultural Heritage by : Gilberto Artioli

Download or read book The Contribution of Mineralogy to Cultural Heritage written by Gilberto Artioli and published by Emu Notes in Mineralogy. This book was released on 2019-09-09 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: The chapters contributed to this book recognize the important and diverse contributions of mineralogy to the valorization, characterization, interpretation and conservation of cultural heritage. The book focuses on examples of materials and methodological issues rather than technical/analytical details.

Carbonatite Volcanism

Download Carbonatite Volcanism PDF Online Free

Author : Keith Bell
Publisher : Springer Science & Business Media
ISBN 13 : 3642791824
Total Pages : 315 pages
Book Rating : 4.6/5 (427 download)

Book Synopsis Carbonatite Volcanism by : Keith Bell

Download or read book Carbonatite Volcanism written by Keith Bell and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last few years, carbonatites have received a considerable amount of attention. Some of this interest was no doubt kindled by the importance of volatiles in the Earth's mantle, particularly CO , by the fact that carbonatites 2 can be used to monitor the chemical evolution of the sub-continental upper mantle, and by the fact that carbonatites may be effective metasomatizing agents at both mantle and crustal levels. The interest in Oldoinyo Lengai has extended over at least 100 years, but it was not until the eruptions of 1960, when the unique carbonatitic nature of its lavas was recognized, that the volcano took on special significance in volcanology and igneous petrology. The recognition of carbonatitic flows coin cided with the first successful laboratory experiments carried out on carbonatitic melts. Since then, Oldoinyo Lengai has formed a cornerstone in all carbonatite discussions. It is probably true to say that the findings from Oldoinyo Lengai have dominated our ideas about carbonatites, in spite of the fact that the alkali rich, natrocarbonatitic lavas of Oldoinyo Lengai are markedly different from other carbonatites.

Trading Paintings and Painters' Materials

Download Trading Paintings and Painters' Materials PDF Online Free

Author : Anne Haack Christensen
Publisher :
ISBN 13 : 9781909492714
Total Pages : 170 pages
Book Rating : 4.4/5 (927 download)

Book Synopsis Trading Paintings and Painters' Materials by : Anne Haack Christensen

Download or read book Trading Paintings and Painters' Materials written by Anne Haack Christensen and published by . This book was released on 2019-07-08 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: The papers in this volume were presented at the CATS international technical art history conference Trading Paintings and Painters' Materials 1550-1800 which explored international markets for paintings and artists' materials in the early modern period and their implications for artistic production. Questions central to these papers include: did preferences exist for artists' materials and paintings from specific geographical areas in particular places and if so why? How did the import of painting materials and artworks impact local production, connoisseurship and art theory? In what conditions were these artists' materials and finished artworks produced and traded in early modern Europe and beyond? The lavishly illustrated contributions in this volume deal with the above questions and shed light on different trades, products, countries and timeframes by combining a large variety of methods and sources, including visual analyses, written sources, pigment analyses and archaeological excavations. This fourth CATS Proceedings will be of interest to scholars and students, museum professionals, curators, conservators, art historians and conservation scientists.

The Oxford Handbook of Archaeological Ceramic Analysis

Download The Oxford Handbook of Archaeological Ceramic Analysis PDF Online Free

Author : Alice M. W. Hunt
Publisher : Oxford University Press
ISBN 13 : 0199681538
Total Pages : 777 pages
Book Rating : 4.1/5 (996 download)

Book Synopsis The Oxford Handbook of Archaeological Ceramic Analysis by : Alice M. W. Hunt

Download or read book The Oxford Handbook of Archaeological Ceramic Analysis written by Alice M. W. Hunt and published by Oxford University Press. This book was released on 2017 with total page 777 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume draws together topics and methodologies essential for the socio-cultural, mineralogical, and geochemical analysis of archaeological ceramic, one of the most complex and ubiquitous archaeomaterials in the archaeological record. It provides an invaluable resource for archaeologists, anthropologists, and archaeological materials scientists.

Fly Ash Zeolites

Download Fly Ash Zeolites PDF Online Free

Author : Bhagwanjee Jha
Publisher : Springer
ISBN 13 : 9811014043
Total Pages : 233 pages
Book Rating : 4.8/5 (11 download)

Book Synopsis Fly Ash Zeolites by : Bhagwanjee Jha

Download or read book Fly Ash Zeolites written by Bhagwanjee Jha and published by Springer. This book was released on 2016-05-27 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a thorough review of the state-of-knowledge and recent innovations in the synthesis of pure and improved grades of fly ash zeolites (FAZ). Addressing improvements to conventional methods, it also showcases a novel technique for the synthesis of high cation exchangers from fly ash and detailed characterization techniques for the products obtained. In addition, it examines in detail various areas of specific applications of fly ash zeolites. Over the years, several methods such as hydrothermal, fusion prior to hydrothermal, microwave assisted hydrothermal and molten salt techniques for producing FAZ have been developed. However, one-step and two-step reactions between the fly ash and alkali usually generate alkaline wastes that may cause environmental contamination. In addition, the separation of FAZ from the partially activated fly ash (the impurities) remains a major concern for researchers and industrialists alike. /divIn view of these challenges, this book presents a novel technique for three-step activation (TSA), which focuses on recycling the fly ash-NaOH-water reaction by-products until zeolitic residue is formed. The FAZ (the final residue after third step reactions) synthesized in this manner exhibits exceptionally high cation exchange capacity, specific surface area and pore area. This book offers a comprehensive compendium of reading material on fly ash and its recycled product, the zeolites. Students at both undergraduate and graduate levels, researchers, and practicing engineers will all find this book to be a valuable guide in their respective fields.

Single Precision Floating Point Multiplier

Download Single Precision Floating Point Multiplier PDF Online Free

Author : B. Vinoth Kumar
Publisher : Anchor Academic Publishing
ISBN 13 : 3960676557
Total Pages : 66 pages
Book Rating : 4.9/5 (66 download)

Book Synopsis Single Precision Floating Point Multiplier by : B. Vinoth Kumar

Download or read book Single Precision Floating Point Multiplier written by B. Vinoth Kumar and published by Anchor Academic Publishing. This book was released on 2017-06-12 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Floating Point Multiplier is a wide variety for increasing accuracy, high speed and high performance in reducing delay, area and power consumption. The floating point is used for algorithms of Digital Signal Processing and Graphics. Many floating point multipliers are used to reduce the area that perform in both the single precision and the double precision in multiplication, addition and subtraction. Here, the scientific notations sign bit, mantissa and exponent are used. The real numbers are divided into two components: fixed component of significant range (lack of dynamic range) and exponential component in floating point (largest dynamic range). The authors convert decimal to floating point and normalize the exponent part and rounding operation to reduce latency. The mantissa of two values are multiplied and the exponent part is added. The sign results with exclusive-or are obtained. Then, the final result of shift and add floating point multiplier is compared with booth multiplication.

Landscapes and Landforms of Ethiopia

Download Landscapes and Landforms of Ethiopia PDF Online Free

Author : Paolo Billi
Publisher : Springer
ISBN 13 : 9401780269
Total Pages : 384 pages
Book Rating : 4.4/5 (17 download)

Book Synopsis Landscapes and Landforms of Ethiopia by : Paolo Billi

Download or read book Landscapes and Landforms of Ethiopia written by Paolo Billi and published by Springer. This book was released on 2015-03-23 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a succinct but comprehensive presentation of key geomorphological locations and topics including information about geomorphological heritage and maps to visit the most important sites. Apart from often being remarkably scenic, landscapes reveal stories that often can be traced back in time tens of million years and include unique events. This is particularly true for Ethiopia where spectacular examples of different landforms are present. Its geomorphology varies from highlands, marked by high volcanoes and incised by deep river gorges, to the rift valley lakes endorheic systems and the below sea level lowlands with characteristic landscapes which are unique in the world. Landscapes and Landforms of Ethiopia highlights all these topics including essential information about geology and tectonic framework, past and present climate, hydrology, geographical regions and long-term geomorphological history. It is a highly informative book, providing insight for readers with an interest in geography and geomorphology.

Global Heritage Stone

Download Global Heritage Stone PDF Online Free

Author : D. Pereira
Publisher : Geological Society of London
ISBN 13 : 186239685X
Total Pages : 278 pages
Book Rating : 4.8/5 (623 download)

Book Synopsis Global Heritage Stone by : D. Pereira

Download or read book Global Heritage Stone written by D. Pereira and published by Geological Society of London. This book was released on 2015-06-04 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Special Publication is dedicated to heritage stone: those natural stones that have special significance in human culture. Some stones that have had important uses in the past are now neglected because they are no longer extracted. Others are still commercially important, but their heritage uses have not been well documented in widely available sources. The Heritage Stone Task Group of the International Union of Geological Sciences is working to establish a new formal designation of ‘Global Heritage Stone Resource’ to recognize those stones that have had internationally significant architectural and ornamental uses. The aim is to spread awareness of the cultural heritage aspects of these stones, to help to encourage continued supply for maintenance and repair of important monuments and to preserve historically important quarries. The aim is neither to promote nor to limit these stones for new construction: in some cases continuing commercial use might help to ensure future supplies for building conservation purposes.

Infrared spectra of mineral species

Download Infrared spectra of mineral species PDF Online Free

Author : Nikita V. Chukanov
Publisher : Springer Science & Business Media
ISBN 13 : 9400771282
Total Pages : 1733 pages
Book Rating : 4.4/5 (7 download)

Book Synopsis Infrared spectra of mineral species by : Nikita V. Chukanov

Download or read book Infrared spectra of mineral species written by Nikita V. Chukanov and published by Springer Science & Business Media. This book was released on 2013-12-03 with total page 1733 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last 30 years, Dr. Nikita V. Chukanov has collected IR spectra of about 2000 mineral species, including 247 holotype samples. In this book, he presents 3309 spectra of these minerals with detailed description and analytical data for reference samples. In the course of this work, about 150 new mineral species have been discovered. After an introductory chapter, infrared spectra of minerals are given together with the descriptions of standard samples used (occurrence, appearance, associated minerals, empirical formula etc.) and some comments. Sections are organized according to different classes of compounds (silicates, phosphates, arsenates, oxides etc.).

The Intangible Elements of Culture in Ethnoarchaeological Research

Download The Intangible Elements of Culture in Ethnoarchaeological Research PDF Online Free

Author : Stefano Biagetti
Publisher : Springer
ISBN 13 : 3319231537
Total Pages : 332 pages
Book Rating : 4.3/5 (192 download)

Book Synopsis The Intangible Elements of Culture in Ethnoarchaeological Research by : Stefano Biagetti

Download or read book The Intangible Elements of Culture in Ethnoarchaeological Research written by Stefano Biagetti and published by Springer. This book was released on 2016-06-02 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume focuses on the intangible elements of human cultures, whose relevance in the study of archaeology has often been claimed but rarely practiced. In this book, the authors successfully show how the adoption of ethnoarchaeological perspectives on non-material aspects of cultures can support the development of methodologies aimed at refining the archaeological interpretation of ancient items, technologies, rituals, settlements and even landscape. The volume includes a series of new approaches that can foster the dialogue between archaeology and anthropology in the domain of the intangible knowledge of rural and urban communities. The role of ethnoarchaeology in the study of the intangible heritage is so far largely underexplored, and there is a considerable lack of ethnoarchaeological studies explicitly focused on the less tangible evidence of present and past societies. Fresh case studies will revitalize the theoretical debate around ethnoarchaeology and its applicability in the archaeological and heritage research in the new millennium. Over the past decade, ‘intangible’ has become a key word in anthropological research and in heritage management. Archaeological theories and methods regarding the explorations of the meaning and the significance of artifacts, resources, and settlement patterns are increasingly focusing on non-material evidence. Due to its peculiar characteristics, ethnoarchaeology can effectively foster the development of the study of the intangible cultural heritage of living societies, and highlight its relevance to the study of those of the past.

Coastal Tectonics

Download Coastal Tectonics PDF Online Free

Author : Iain S. Stewart
Publisher : Geological Society of London
ISBN 13 : 9781862390249
Total Pages : 390 pages
Book Rating : 4.3/5 (92 download)

Book Synopsis Coastal Tectonics by : Iain S. Stewart

Download or read book Coastal Tectonics written by Iain S. Stewart and published by Geological Society of London. This book was released on 1998 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: